Underreamer



C. S. WRIGHT.

UNDERREAMER. APPLICATION H'LED APR. 5, 1920.

Patnted Aug. 24,1920.

2 SHEETS-SHEET l.

a u w Vl//I//m//l////7///////////// /////////l////l//////I //l///lI/l/////////////!I////////////////////////1/1/1/1//// citizen of the United States, residin UNITED STATES GLYDE S. WEIGHT, OF TOLEDO, OHIO, ASSIGNOR TO THE NATIONAL SUPPLY COMPANY OF TOLEDO, OHIO, A CORPORATION OF OHIO.

PATENT OFFICE.

Speciflcation ofcLetters Patent. Patented Aug. 24, 1920.

Application'flled April 5, 192 0. Serial No. 371320.

To all 'whom it may concem:

Be it known that I CLYDE S. WRIGHT, a at Toledo, in the county of Lucas and tate of Ohio, have invented new and useful Improvementsin Underreanlers, of which the following is a s'pecification.

My invention relates to underreamers for reaming the sides of wells below their cas- %he object of the present invention is to provide an underreamer simple in Construction and containing but few parts. Another object is to reduce the cost of manufacture of underreamers by making the bore of the body circular so that very sim le machining Operations are required. he cutters have surfaces curved on the arcs of circles wherever possible for the same reason. A- 'other object is to design the parts so that the bits or cutters may be readly inserted into and removed from the body and readily collapsed for insertion of the underreamer into the top of the well casing and for pulling it into the lower end of the casing when it is desired to remove the tool from a well. Other minor objects appearhereinafter. e

Referring to the accompanyng drawings, Figure 1 is a central longitudinal section of my improved underreamer with the cutters expanded just below the casing, ready to begin a reaming operation or to be withdrawn from the well, parts of the view being in side elevation; Fig. 2, a View similar to Fig. 1, but with the cutters just ready to be collapsedduring the operation of pulling the underreamer into the casing; Fig. 3, a View similar to Fig. 2, but with the cutters' fully collapsed and the underreamer withdrawn into the casing; Fg. 4,. a sectional View of a part of the body of the tool, the view illustrating the method of assembling the underreamer; Fig, 5, a longitudinal section of a part of the body and a side elevation of the cutters and parts coope'rating therewith, the view showing the method of collapsing the cutters preparatory to inserting the underreamer into the top of a well casing; and Fi 6, a cross-section on the line V -VI of. ig. 2. Fig. 7 is a bottom lan view of 'the underreamer as shown in i 1.

On the drawngs, 1 designates the underreamer body and 2 the sub attachable thereto by the usual tapered pin and box connection 3. The body is hollow or centrally bored from end to end, the holl ow having the several sections 4, 5, 6, 7, and 8 of difl'erent diameters and shapes, all symmetrically dsposed around the longitudinal axis of the bodywhich is in general cylindrical.

The section 4 is at the lower end of the body and is frusto-conical in sha e tapering upwardly to the annular shoul er 9. The section 5 is an opening preferably cylindrical, communicating with the section 4 and having its diameter somewhat shorter than that of the upper end of the section 4:. The section 6 is a cylindrical opening having a larger diameter than the section 5. The section 8 is a cylindrical bore at the upper end of the body, and is connected to the section 6 b the smaller cylindrical section 7.

ithin the sections 4:, 5, and 6 are the tangs of the two cutters or bits 10 and 11. The tangs have horizontally curved and upwardly tapering portions 12 fitting the curve and taper of the section 4, and havin the shoulders 13 seated against the shoul er 9 when the cutters are n working positions, as shown on Fig. 1. The cutters 10 and 11 have respectively the inner or opposing lugs or shoulders 14 and 15 having and 18 preferably parallel with the body 1, these faces registering or engaging each other when the cutters are in said working position to hold the cutters expanded. The lug 14 has the inclined face or shoulder 19 extending downwardly and outwardly from the lower end of the face 17, and the cutter 11 has the` correspondingly inclined face or shoulder 20 extending upwardly and outwardly from the upper end of the face 18, so that, when the cutter 11 is moved downwardly with the inclined faces in 'the same plane, the cutters may move one toward the other during any further downward movement of the cutter 11 until the cutters are fully collapsed, as in Fig. 3, and the inclined faces 19 and 20 lie squarely on each other.

The opposing faces of the portions 12: of the cutter-tangs have recesses, the recess 31 in the cutter 11 being but slightly, if at all, longer than the length of the nut 32 having one side seated therein, while the recess 33 in the cutter 10 extends from the lug 14: up to the level of the top of the recess 31 when the cutters are in workin positions. The recess 33 is a seat and sli eway for the adthe faces 17 jacent side 'of 'the nut 32. The recesses 31 i and 33 have their inner parts angular to reupper end of the rod 36 which extends downw'ardly through the spring and the section 7, whence it extends down between the tangs 'of the cutters, its lower end being threaded and screwed into the nut 32. The head 35 has the flat upper extension 37 lying between the two cross pins 38 extending through the walls at'the upper end of the body and preventing the rod from turnng. Before-the pins are inserted the flat extension may have a wrench fitted thereon for turning the rod 36 to screw it into the nut 32. The spring 34 causes the nut 32 to hold the cutters with their shoulders 13 against the shoulders 9. i

Above the tapered portions 12 of the cutters 10 and 11, the tangs have their respective necks 21 and 22 in the section 5. he

cutter 10 has the head 23 at the upper end of its tang, this head being in the section 6 and having its semi-annular lower end seated on the -shoulder 24 at the bottom of the section 6, so that the neck 21 of the cutter 10.

is about as long as the section 5, this cutter therefore having substantially no longtudinal travel from the position shown on Figs. 1 and 2. Preferably the head 23 extends close to the top of the section 6, the

upper end of the head being tapered upwardly so that the cutter 10 may be swung inwardly without lessening the space' between this head and the head 25 on the top of the other cutter 11. 'The head 25 is considerably s'horter than the length of the section. 6 and stands opposite the tapered sec- .tion'of the head 23 when the cutters are both in working positions. The cutter 11, therefore, has its neck 22 extended considerablyup beyond the shoulder 13 and into the section 6, so that the cutter 11 may be drawn downwardly. The opposing portions of the tangs in the section 6 are inclined upwardlyand outwardly at 26 to provide clearance for the insertion and removal of the cutter 11. The lower ends of the cutters have the usual cutting edges 27, The cutter 10 has the external shoulder 28 seated on the lower end of the body 1 and is flush therewith 'when the cutter is in Operating position.

The cutter 11 has the external shoulder 29 'seated on the lower end'of the body 1 when the cutter is in working position. The

shoulder 29'extends out laterally slightly' beyond the outer surface of the body 1 as 7 shown-on Fig. 1, the outer part of the shoulder being somewhat rounded or inclined downwardly and outwardly.

When the underreamer body is drawn upwardly in the operation of taking it out of the well, the shoulder 29 will engage the beveled lower end of the well casing 30 and restrain the cutter 11 from traveling upwardly with the body 1 and the cutter 10 until the incline 19 reaches the plane of the incline 20. As the body and the cutter 10 travel farther upwardly the cutter 11 swings toward the cutter 10, the face 19 riding up on the face 20 as the shoulder 29 forces the cutter 11 inwardly and the nut 32 rides down the recess 33. s the tool is drawn up farther into the casing the downwardly flaring faces of the cutters riding into the casing forces the cutters inwardly and the cutter 11 downwardly relatively to the cutter 10 until the cutters are entirely within the casing. The cutter 10 has the external shoulder 28' located somewhat lower than the shoulder 28, so that the described function of the shoulder 29 will not be interfered with. This shoulder 28' assists in the collapsing of the cutters.

. The method of assembling the underreamer is partially illustrated in Fig. 4. The cutter 10 is first seated in its normal position with respect to the body 1 by simply inserting its tang therein with the head 23 in the section 6 and the part 12 in the.

section 4, as shown on Fig. 4. The nut 32 is next inserted into the recess 33, and the cutter 11 is then inserted through the section 4 until the recess 31 comes opposite the nut, whereupon the cutter 11 can be swung toward the cutter 10, the recess 31 coVering the adjacent side of the nut. The cutter 11 can then be shoved up to its normal'position in'the body 1. The rod 36 is then inserted through the spring' 34 and between the cutter-tangs and screwed into the nut. The pins 38 are next put in place and the sub 2 screwedon the body 1.

In order to collapse the cutters before introducing the underreamer into the well, a

'32 riding down the recess 33. When the in- .clined surfaces on the cutters are opposite,

the cutters are moved toward each other until these surfaces interengage. Then the open ring 43 is placed around' the cuttersto prevent their expanding. The lever and the clevis with its bolt 40 are removed and the cutter end of the underreamer is let down into the casing. The ring 43 is stopped by the end of the casing and the underreamer, passes down the casmg, the cutters sliding on the inner wall of the casing. When the .flat 44 for applying a wrench comes oppoposition, which is shown on Fig. 1.

It will be notedthat, when the cutters are expanded as shown in F ig. 1, the lugs 14:

and 15 and the remaining parts of the cutters about the lower end of the body- 1`entirely close the bottom of the body, thereby keeping drillings out of the interior of the .body. If the drillings have access to the interier of the body, they might become packed in the space between the cutters and beneath the head 25 and prevent the Collapsing of the cutters and, consequently, the withd'rawal of the underreamer from the well. The lugs 14: and 15 extend entirely across the space between the downward extensions 45 of the sides of the body 1, the inne'r faces of the extensions being flat and fitting the correspondingly flat faces of the cutters and their -lugs 14 and 15.

I do not limit myself to the elements and combinations thereof shown and described, as many changes may be made therein'without departing .from the spirit of my invention.

I claim:

. 1. In an underreamer, a pair. of opposed expanding cutters having tangs, a body with a bottom recess for the said tangs, means* preventing the longitudinal movement of one cutter, a spring controlled rod lon 'tudinally movable in the body, and a eadt on the rod, and in recesses in opposing faces of the tangs, the head being seated against the inner ends of the recesses when the cutters are expanded, the recess'in the fixed cutter permitting the said head to travel as the othercutter is moved longitudinally out of the body.

2. In an underreamer, abody having at one end a' socket widening toward that end, a pair of expandingcutters having tangs insertible into the socket, means preventing the longitudinal travel of one cutter, an headed means between the cutters ,yieldingly restraining the longitudinal travel of the other cutter, the said widening socket providing suficient room for the second cutter laterally beyond the headed means when it has been longitudinally moved outward a predetermined distance whereby the second cutter may be removed from the socket past'the headed means.

3. In an underreamer, a body having at one end a socket widening toward that end, a pair of expanding cutters having tangs insertible into the socket, an inwardly projecting shoulder in the socket, a shoulder on the tang of one cutter coperating with the first shoulder to prevent the longitudinal travel o f that cutter, and means yieldingly restraining the longitudinal travel of the other cutter.

4. In an underreamer, a pair of opposed expanding cutters having tangs, a body with a bottom recess for the, said tangs, an inwardly projecting shoulder in the socket, a

shoulder on the tang of one cutter coperating with the first shoulder to prevent the lon itudinal travel of that cutter, and spring controlled means yieldingly restraining longitudinal movement o the other cutter, whereby' the latter cutter may upon such movement be removed from the body. 5. In an underreamer, a body having an end socket, cutters having tan in the socket, means preventing longitudinal travel of one cutter, the other cutter having longitudinal travel, means yieldingly restraining the travel of the second cutter, abuttin faces on the cutters to hold them expande when the second cutter is in its working position, and a head and shoulder connec- 'tion between the second cutter and the CLYDE S. WEIGHT. i 

